JAJSFO6G December   2015  – July 2024 TPS99000-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics—Transimpedance Amplifier Parameters
    6. 5.6  Electrical Characteristics—Digital to Analog Converters
    7. 5.7  Electrical Characteristics—Analog to Digital Converter
    8. 5.8  Electrical Characteristics—FET Gate Drivers
    9. 5.9  Electrical Characteristics—Photo Comparator
    10. 5.10 Electrical Characteristics—Voltage Regulators
    11. 5.11 Electrical Characteristics—Temperature and Voltage Monitors
    12. 5.12 Electrical Characteristics—Current Consumption
    13. 5.13 Power-Up Timing Requirements
    14. 5.14 Power-Down Timing Requirements
    15. 5.15 Timing Requirements—Sequencer Clock
    16. 5.16 Timing Requirements—Host and Diagnostic Port SPI Interface
    17. 5.17 Timing Requirements—ADC Interface
    18. 5.18 Switching Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Illumination Control
        1. 6.3.1.1 Illumination System High Dynamic Range Dimming Overview
        2. 6.3.1.2 Illumination Control Loop
        3. 6.3.1.3 Continuous Mode Operation
          1. 6.3.1.3.1 Output Capacitance in Continuous Mode
          2. 6.3.1.3.2 Continuous Mode Driver Distortion and Blanking Current
          3. 6.3.1.3.3 Continuous Mode S_EN2 Dissipative Load Shunt Options
          4. 6.3.1.3.4 Continuous Mode Constant OFF Time
          5. 6.3.1.3.5 Continuous Mode Current Limit
        4. 6.3.1.4 Discontinuous Mode Operation
          1. 6.3.1.4.1 Discontinuous Mode Pulse Width Limit
          2. 6.3.1.4.2 COMPOUT_LOW Timer in Discontinuous Operation
          3. 6.3.1.4.3 Dimming Within Discontinuous Operation Range
          4. 6.3.1.4.4 Multiple Pulse Heights to Increase Bit Depth
          5. 6.3.1.4.5 TIA Gain Adjustment
          6. 6.3.1.4.6 Current Limit in Discontinuous Mode
          7. 6.3.1.4.7 CMODE Big Cap Mode in Discontinuous Operation
      2. 6.3.2 Over-Brightness Detection
        1. 6.3.2.1 Photo Feedback Monitor BIST
        2. 6.3.2.2 Excessive Brightness BIST
      3. 6.3.3 Analog to Digital Converter
        1. 6.3.3.1 Analog to Digital Converter Input Table
      4. 6.3.4 Power Sequencing and Monitoring
        1. 6.3.4.1 Power Monitoring
      5. 6.3.5 DMD Mirror Voltage Regulator
      6. 6.3.6 Low Dropout Regulators
      7. 6.3.7 System Monitoring Features
        1. 6.3.7.1 Windowed Watchdog Circuits
        2. 6.3.7.2 Die Temperature Monitors
        3. 6.3.7.3 External Clock Ratio Monitor
      8. 6.3.8 Communication Ports
        1. 6.3.8.1 Serial Peripheral Interface (SPI)
    4. 6.4 Device Functional Modes
      1. 6.4.1 OFF
      2. 6.4.2 STANDBY
      3. 6.4.3 POWERING_DMD
      4. 6.4.4 DISPLAY_RDY
      5. 6.4.5 DISPLAY_ON
      6. 6.4.6 PARKING
      7. 6.4.7 SHUTDOWN
    5. 6.5 Register Maps
      1. 6.5.1 System Status Registers
      2. 6.5.2 ADC Control
      3. 6.5.3 General Fault Status
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 HUD
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Application Design Considerations
          1. 7.2.1.2.1 Photodiode Considerations
          2. 7.2.1.2.2 LED Current Measurement
          3. 7.2.1.2.3 Setting the Current Limit
          4. 7.2.1.2.4 Input Voltage Variation Impact
          5. 7.2.1.2.5 Discontinuous Mode Photo Feedback Considerations
          6. 7.2.1.2.6 Transimpedance Amplifiers (TIAs, Usage, Offset, Dark Current, Ranges, RGB Trim)
      2. 7.2.2 Headlight
        1. 7.2.2.1 Design Requirements
  9. 8 Power Supply Recommendations
    1. 8.1 TPS99000-Q1 Power Supply Architecture
    2. 8.2 TPS99000-Q1 Power Outputs
    3. 8.3 Power Supply Architecture
  10. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 Power/High Current Signals
      2. 9.1.2 Sensitive Analog Signals
      3. 9.1.3 High-Speed Digital Signals
      4. 9.1.4 High Power Current Loops
      5. 9.1.5 Kelvin Sensing Connections
      6. 9.1.6 Ground Separation
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 サード・パーティ製品に関する免責事項
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
6.3.1.3.4 Continuous Mode Constant OFF Time

A constant off time feature (see COMPOUT_LOW signal in Figure 6-13) is included in continuous mode operation. During continuous mode operation, when the desired light level is achieved, the PFET gate drive is turned off by control of the DRV_EN signal and the light level begins to decrease as the inductor current begins to decrease. In a typical hysteretic controller, when a turn on threshold is reached, the PFET is turned on and the light/inductor current increases again. The frequency of switching is dependent on the difference between the turn on and turn off thresholds, loop delay and discrete component values (with the inductor inductance and voltage being most dominant factors).

In the TPS99000-Q1, the control is modified to regulate the operating frequency. A constant off timer is included in the TPS99000-Q1 control loop. When the photo feedback comparator threshold is achieved, a counter is started. The length of the counter is adjustable. While this counter is active, the output of the photo feedback comparator is ignored and the PFET drive (via DRV_EN output from TPS99000-Q1) is disabled. Once the constant off time period counter has expired, the output of the photo feedback comparator is once again used to control the LED current drive. The minimum off-time establishes an upper limit on the hysteretic control loop switching frequency, separate from the natural frequency of the circuit. This feature is useful for assuring the circuit will not operate in the AM radio frequency band, and can also enable the usage of lower inductance value inductors (which can result in system cost savings and power efficiency improvements).

TPS99000-Q1 COMPOUT_LOW Constant Off TimeFigure 6-13 COMPOUT_LOW Constant Off Time